DON抑制小麦种胚细胞周期启动的研究

小麦种子在０．５－４．０ｍｇ／Ｌ的脱氧雪腐镰刀菌烯醇（ＤＯＮ）中溶液中萌发，用流式细胞仪检测胚细胞的周期时相并观察黄化苗的生长。结果表明，对照组胚细胞在萌发１２ｈ开始启动细胞周期，此后Ｓ期细胞比率迅速增加并在２０ｈ达到最大值，较萌发１０ｈ的６．５％增加１．７８倍，约１４％的胚细胞在萌发的２２－２６ｈ间完成第一次分裂；ＤＯＮ抑制Ｇ１期胚细胞的启动，小麦胚中Ｓ期细胞比率随ＤＯＮ浓度增加呈指数下降，３．

Inhibition Effect of DON on Cell Cycle Activation in Wheat Embryo Cells

The activation of the cell cycle in embryo cells of wheat (Triticum aestivum L., cv. Lu-Mai No. 22) seeds imbibing in 0.5～4.0 mg/L deoxynivalenol (DON) was studied by flow cytometric analyses. The results indicated that the majority of the embryo cells in wheat seeds were arrested at the G1 phase of the cell cycle. The cell cycle was activated after the seeds imbibing in distilled water for 12　h, and then the relative percentage of S-phase cells in wheat embryos were observed to increase steadily until a peak was reached on the 20　h imbibition. The number of S-phase cells in wheat embryos imbibing in water for 20　h was 1.78 fold more than that imbibing for 10　h. When imbibing for 22 to 26 h, about 14% embryo cells in wheat seeds had finished their mitosis. The entry of the embryo cells at G1 phase into S phase was strongly inhibited by imbibing the seeds in DON solution. The percentage of wheat embryo cells at S phase decreased exponentially with increasing concentration of DON treatment up to 4.0 mg/L. Embryo cells in wheat seeds could be blocked completely at G1 phase and S phase by 3.5 and 2.0 mg/L DON treatment respectively. The seedling height and radicle length decreased linearly with increasing concentration of DON, while root number of etiolated wheat seedlings was accelerated by DON with a maximal stimulation concentration of 1.5 mg/L. These data suggest that the inhibition of wheat germination by DON results in inhibition of cell cycle activation in embryo cells.